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<meta charset=utf-8>
<meta name="timeout" content="long">
<title>RTCPeerConnection Codecs in subsequent offer</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../third_party/sdp/sdp.js"></script>
<script>
'use strict';

// A test for https://www.rfc-editor.org/rfc/rfc8829.html#name-subsequent-offers
// The "m=" line and corresponding "a=rtpmap" and "a=fmtp" lines MUST only include
// media formats that have not been excluded by the codec preferences of the
// associated transceiver and also MUST include all currently available formats.

// A VP8-only offer.
const sdp = `v=0
o=- 0 3 IN IP4 127.0.0.1
s=-
t=0 0
a=fingerprint:sha-256 A7:24:72:CA:6E:02:55:39:BA:66:DF:6E:CC:4C:D8:B0:1A:BF:1A:56:65:7D:F4:03:AD:7E:77:43:2A:29:EC:93
m=video 9 RTP/SAVPF 100
c=IN IP4 0.0.0.0
a=rtcp-mux
a=sendrecv
a=mid:video
a=rtpmap:100 VP8/90000
a=setup:actpass
a=ice-ufrag:ETEn
a=ice-pwd:OtSK0WpNtpUjkY4+86js7Z/l
`;

promise_test(async t => {
  const pc = new RTCPeerConnection();
  t.add_cleanup(() => pc.close());

  await pc.setRemoteDescription({type: 'offer', sdp});
  await pc.setLocalDescription();
  const transceiver = pc.getTransceivers()[0];
  assert_not_equals(transceiver.stopped, true);
  const offer = await pc.createOffer();
  const mediaSection = SDPUtils.getMediaSections(offer.sdp)[0];
  const rtpParameters = SDPUtils.parseRtpParameters(mediaSection);
  const vp8 = rtpParameters.codecs.filter(codec => codec.name === 'VP8');
  const h264 = rtpParameters.codecs.filter(codec => codec.name === 'H264');
  assert_greater_than(vp8.length, 0);
  assert_greater_than(h264.length, 0);
}, 'A subsequent offer after a VP8-only negotiation includes at least all mandatory to implement codecs');

</script>
